Commit message: irda: prevent integer underflow in IRLMP_ENUMDEVICES

If the user-provided len is less than the expected offset, the
IRLMP_ENUMDEVICES getsockopt will do a copy_to_user() with a very large
size value.  While this isn't be a security issue on x86 because it will
get caught by the access_ok() check, it may leak large amounts of kernel
heap on other architectures.  In any event, this patch fixes it.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
CVE: None
Vulnerability description: None

Project: linux
File: af_irda.c

static void irda_selective_discovery_indication(discinfo_t *discovery,
						DISCOVERY_MODE mode,
						void *priv)
{
	struct irda_sock *self;

	IRDA_DEBUG(2, "%s()\n", __func__);

	self = (struct irda_sock *) priv;
	if (!self) {
		IRDA_WARNING("%s: lost myself!\n", __func__);
		return;
	}

	/* Pass parameter to the caller */
	self->cachedaddr = discovery->daddr;

	/* Wake up process if its waiting for device to be discovered */
	wake_up_interruptible(&self->query_wait);
}

Project: linux
File: af_irda.c

static int irda_sendmsg(struct kiocb *iocb, struct socket *sock,
			struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	struct irda_sock *self;
	struct sk_buff *skb;
	int err = -EPIPE;

	IRDA_DEBUG(4, "%s(), len=%zd\n", __func__, len);

	/* Note : socket.c set MSG_EOR on SEQPACKET sockets */
	if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_EOR | MSG_CMSG_COMPAT |
			       MSG_NOSIGNAL)) {
		err = -EINVAL;
		goto out;
	}

	lock_sock(sk);

	if (sk->sk_shutdown & SEND_SHUTDOWN)
		goto out_err;

	if (sk->sk_state != TCP_ESTABLISHED) {
		err = -ENOTCONN;
		goto out;
	}

	self = irda_sk(sk);

	/* Check if IrTTP is wants us to slow down */

	if (wait_event_interruptible(*(sk_sleep(sk)),
	    (self->tx_flow != FLOW_STOP  ||  sk->sk_state != TCP_ESTABLISHED))) {
		err = -ERESTARTSYS;
		goto out;
	}

	/* Check if we are still connected */
	if (sk->sk_state != TCP_ESTABLISHED) {
		err = -ENOTCONN;
		goto out;
	}

	/* Check that we don't send out too big frames */
	if (len > self->max_data_size) {
		IRDA_DEBUG(2, "%s(), Chopping frame from %zd to %d bytes!\n",
			   __func__, len, self->max_data_size);
		len = self->max_data_size;
	}

	skb = sock_alloc_send_skb(sk, len + self->max_header_size + 16,
				  msg->msg_flags & MSG_DONTWAIT, &err);
	if (!skb)
		goto out_err;

	skb_reserve(skb, self->max_header_size + 16);
	skb_reset_transport_header(skb);
	skb_put(skb, len);
	err = memcpy_fromiovec(skb_transport_header(skb), msg->msg_iov, len);
	if (err) {
		kfree_skb(skb);
		goto out_err;
	}

	/*
	 * Just send the message to TinyTP, and let it deal with possible
	 * errors. No need to duplicate all that here
	 */
	err = irttp_data_request(self->tsap, skb);
	if (err) {
		IRDA_DEBUG(0, "%s(), err=%d\n", __func__, err);
		goto out_err;
	}

	release_sock(sk);
	/* Tell client how much data we actually sent */
	return len;

out_err:
	err = sk_stream_error(sk, msg->msg_flags, err);
out:
	release_sock(sk);
	return err;

}

Project: linux
File: af_irda.c

static int irda_recvmsg_stream(struct kiocb *iocb, struct socket *sock,
			       struct msghdr *msg, size_t size, int flags)
{
	struct sock *sk = sock->sk;
	struct irda_sock *self = irda_sk(sk);
	int noblock = flags & MSG_DONTWAIT;
	size_t copied = 0;
	int target, err;
	long timeo;

	IRDA_DEBUG(3, "%s()\n", __func__);

	if ((err = sock_error(sk)) < 0)
		return err;

	if (sock->flags & __SO_ACCEPTCON)
		return -EINVAL;

	err =-EOPNOTSUPP;
	if (flags & MSG_OOB)
		return -EOPNOTSUPP;

	err = 0;
	target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
	timeo = sock_rcvtimeo(sk, noblock);

	msg->msg_namelen = 0;

	do {
		int chunk;
		struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);

		if (skb == NULL) {
			DEFINE_WAIT(wait);
			err = 0;

			if (copied >= target)
				break;

			prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);

			/*
			 *	POSIX 1003.1g mandates this order.
			 */
			err = sock_error(sk);
			if (err)
				;
			else if (sk->sk_shutdown & RCV_SHUTDOWN)
				;
			else if (noblock)
				err = -EAGAIN;
			else if (signal_pending(current))
				err = sock_intr_errno(timeo);
			else if (sk->sk_state != TCP_ESTABLISHED)
				err = -ENOTCONN;
			else if (skb_peek(&sk->sk_receive_queue) == NULL)
				/* Wait process until data arrives */
				schedule();

			finish_wait(sk_sleep(sk), &wait);

			if (err)
				return err;
			if (sk->sk_shutdown & RCV_SHUTDOWN)
				break;

			continue;
		}

		chunk = min_t(unsigned int, skb->len, size);
		if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
			skb_queue_head(&sk->sk_receive_queue, skb);
			if (copied == 0)
				copied = -EFAULT;
			break;
		}
		copied += chunk;
		size -= chunk;

		/* Mark read part of skb as used */
		if (!(flags & MSG_PEEK)) {
			skb_pull(skb, chunk);

			/* put the skb back if we didn't use it up.. */
			if (skb->len) {
				IRDA_DEBUG(1, "%s(), back on q!\n",
					   __func__);
				skb_queue_head(&sk->sk_receive_queue, skb);
				break;
			}

			kfree_skb(skb);
		} else {
			IRDA_DEBUG(0, "%s() questionable!?\n", __func__);

			/* put message back and return */
			skb_queue_head(&sk->sk_receive_queue, skb);
			break;
		}
	} while (size);

	/*
	 *  Check if we have previously stopped IrTTP and we know
	 *  have more free space in our rx_queue. If so tell IrTTP
	 *  to start delivering frames again before our rx_queue gets
	 *  empty
	 */
	if (self->rx_flow == FLOW_STOP) {
		if ((atomic_read(&sk->sk_rmem_alloc) << 2) <= sk->sk_rcvbuf) {
			IRDA_DEBUG(2, "%s(), Starting IrTTP\n", __func__);
			self->rx_flow = FLOW_START;
			irttp_flow_request(self->tsap, FLOW_START);
		}
	}

	return copied;
}

Project: linux
File: af_irda.c

static int irda_getsockopt(struct socket *sock, int level, int optname,
			   char __user *optval, int __user *optlen)
{
	struct sock *sk = sock->sk;
	struct irda_sock *self = irda_sk(sk);
	struct irda_device_list list;
	struct irda_device_info *discoveries;
	struct irda_ias_set *	ias_opt;	/* IAS get/query params */
	struct ias_object *	ias_obj;	/* Object in IAS */
	struct ias_attrib *	ias_attr;	/* Attribute in IAS object */
	int daddr = DEV_ADDR_ANY;	/* Dest address for IAS queries */
	int val = 0;
	int len = 0;
	int err = 0;
	int offset, total;

	IRDA_DEBUG(2, "%s(%p)\n", __func__, self);

	if (level != SOL_IRLMP)
		return -ENOPROTOOPT;

	if (get_user(len, optlen))
		return -EFAULT;

	if(len < 0)
		return -EINVAL;

	lock_sock(sk);

	switch (optname) {
	case IRLMP_ENUMDEVICES:

		/* Offset to first device entry */
		offset = sizeof(struct irda_device_list) -
			sizeof(struct irda_device_info);

		if (len < offset) {
			err = -EINVAL;
			goto out;
		}

		/* Ask lmp for the current discovery log */
		discoveries = irlmp_get_discoveries(&list.len, self->mask.word,
						    self->nslots);
		/* Check if the we got some results */
		if (discoveries == NULL) {
			err = -EAGAIN;
			goto out;		/* Didn't find any devices */
		}

		/* Write total list length back to client */
		if (copy_to_user(optval, &list, offset))
			err = -EFAULT;

		/* Copy the list itself - watch for overflow */
		if (list.len > 2048) {
			err = -EINVAL;
			goto bed;
		}
		total = offset + (list.len * sizeof(struct irda_device_info));
		if (total > len)
			total = len;
		if (copy_to_user(optval+offset, discoveries, total - offset))
			err = -EFAULT;

		/* Write total number of bytes used back to client */
		if (put_user(total, optlen))
			err = -EFAULT;
bed:
		/* Free up our buffer */
		kfree(discoveries);
		break;
	case IRLMP_MAX_SDU_SIZE:
		val = self->max_data_size;
		len = sizeof(int);
		if (put_user(len, optlen)) {
			err = -EFAULT;
			goto out;
		}

		if (copy_to_user(optval, &val, len)) {
			err = -EFAULT;
			goto out;
		}

		break;
	case IRLMP_IAS_GET:
		/* The user want an object from our local IAS database.
		 * We just need to query the IAS and return the value
		 * that we found */

		/* Check that the user has allocated the right space for us */
		if (len != sizeof(struct irda_ias_set)) {
			err = -EINVAL;
			goto out;
		}

		ias_opt = kmalloc(sizeof(struct irda_ias_set), GFP_ATOMIC);
		if (ias_opt == NULL) {
			err = -ENOMEM;
			goto out;
		}

		/* Copy query to the driver. */
		if (copy_from_user(ias_opt, optval, len)) {
			kfree(ias_opt);
			err = -EFAULT;
			goto out;
		}

		/* Find the object we target.
		 * If the user gives us an empty string, we use the object
		 * associated with this socket. This will workaround
		 * duplicated class name - Jean II */
		if(ias_opt->irda_class_name[0] == '\0')
			ias_obj = self->ias_obj;
		else
			ias_obj = irias_find_object(ias_opt->irda_class_name);
		if(ias_obj == (struct ias_object *) NULL) {
			kfree(ias_opt);
			err = -EINVAL;
			goto out;
		}

		/* Find the attribute (in the object) we target */
		ias_attr = irias_find_attrib(ias_obj,
					     ias_opt->irda_attrib_name);
		if(ias_attr == (struct ias_attrib *) NULL) {
			kfree(ias_opt);
			err = -EINVAL;
			goto out;
		}

		/* Translate from internal to user structure */
		err = irda_extract_ias_value(ias_opt, ias_attr->value);
		if(err) {
			kfree(ias_opt);
			goto out;
		}

		/* Copy reply to the user */
		if (copy_to_user(optval, ias_opt,
				 sizeof(struct irda_ias_set))) {
			kfree(ias_opt);
			err = -EFAULT;
			goto out;
		}
		/* Note : don't need to put optlen, we checked it */
		kfree(ias_opt);
		break;
	case IRLMP_IAS_QUERY:
		/* The user want an object from a remote IAS database.
		 * We need to use IAP to query the remote database and
		 * then wait for the answer to come back. */

		/* Check that the user has allocated the right space for us */
		if (len != sizeof(struct irda_ias_set)) {
			err = -EINVAL;
			goto out;
		}

		ias_opt = kmalloc(sizeof(struct irda_ias_set), GFP_ATOMIC);
		if (ias_opt == NULL) {
			err = -ENOMEM;
			goto out;
		}

		/* Copy query to the driver. */
		if (copy_from_user(ias_opt, optval, len)) {
			kfree(ias_opt);
			err = -EFAULT;
			goto out;
		}

		/* At this point, there are two cases...
		 * 1) the socket is connected - that's the easy case, we
		 *	just query the device we are connected to...
		 * 2) the socket is not connected - the user doesn't want
		 *	to connect and/or may not have a valid service name
		 *	(so can't create a fake connection). In this case,
		 *	we assume that the user pass us a valid destination
		 *	address in the requesting structure...
		 */
		if(self->daddr != DEV_ADDR_ANY) {
			/* We are connected - reuse known daddr */
			daddr = self->daddr;
		} else {
			/* We are not connected, we must specify a valid
			 * destination address */
			daddr = ias_opt->daddr;
			if((!daddr) || (daddr == DEV_ADDR_ANY)) {
				kfree(ias_opt);
				err = -EINVAL;
				goto out;
			}
		}

		/* Check that we can proceed with IAP */
		if (self->iriap) {
			IRDA_WARNING("%s: busy with a previous query\n",
				     __func__);
			kfree(ias_opt);
			err = -EBUSY;
			goto out;
		}

		self->iriap = iriap_open(LSAP_ANY, IAS_CLIENT, self,
					 irda_getvalue_confirm);

		if (self->iriap == NULL) {
			kfree(ias_opt);
			err = -ENOMEM;
			goto out;
		}

		/* Treat unexpected wakeup as disconnect */
		self->errno = -EHOSTUNREACH;

		/* Query remote LM-IAS */
		iriap_getvaluebyclass_request(self->iriap,
					      self->saddr, daddr,
					      ias_opt->irda_class_name,
					      ias_opt->irda_attrib_name);

		/* Wait for answer, if not yet finished (or failed) */
		if (wait_event_interruptible(self->query_wait,
					     (self->iriap == NULL))) {
			/* pending request uses copy of ias_opt-content
			 * we can free it regardless! */
			kfree(ias_opt);
			/* Treat signals as disconnect */
			err = -EHOSTUNREACH;
			goto out;
		}

		/* Check what happened */
		if (self->errno)
		{
			kfree(ias_opt);
			/* Requested object/attribute doesn't exist */
			if((self->errno == IAS_CLASS_UNKNOWN) ||
			   (self->errno == IAS_ATTRIB_UNKNOWN))
				err = -EADDRNOTAVAIL;
			else
				err = -EHOSTUNREACH;

			goto out;
		}

		/* Translate from internal to user structure */
		err = irda_extract_ias_value(ias_opt, self->ias_result);
		if (self->ias_result)
			irias_delete_value(self->ias_result);
		if (err) {
			kfree(ias_opt);
			goto out;
		}

		/* Copy reply to the user */
		if (copy_to_user(optval, ias_opt,
				 sizeof(struct irda_ias_set))) {
			kfree(ias_opt);
			err = -EFAULT;
			goto out;
		}
		/* Note : don't need to put optlen, we checked it */
		kfree(ias_opt);
		break;
	case IRLMP_WAITDEVICE:
		/* This function is just another way of seeing life ;-)
		 * IRLMP_ENUMDEVICES assumes that you have a static network,
		 * and that you just want to pick one of the devices present.
		 * On the other hand, in here we assume that no device is
		 * present and that at some point in the future a device will
		 * come into range. When this device arrive, we just wake
		 * up the caller, so that he has time to connect to it before
		 * the device goes away...
		 * Note : once the node has been discovered for more than a
		 * few second, it won't trigger this function, unless it
		 * goes away and come back changes its hint bits (so we
		 * might call it IRLMP_WAITNEWDEVICE).
		 */

		/* Check that the user is passing us an int */
		if (len != sizeof(int)) {
			err = -EINVAL;
			goto out;
		}
		/* Get timeout in ms (max time we block the caller) */
		if (get_user(val, (int __user *)optval)) {
			err = -EFAULT;
			goto out;
		}

		/* Tell IrLMP we want to be notified */
		irlmp_update_client(self->ckey, self->mask.word,
				    irda_selective_discovery_indication,
				    NULL, (void *) self);

		/* Do some discovery (and also return cached results) */
		irlmp_discovery_request(self->nslots);

		/* Wait until a node is discovered */
		if (!self->cachedaddr) {
			IRDA_DEBUG(1, "%s(), nothing discovered yet, going to sleep...\n", __func__);

			/* Set watchdog timer to expire in <val> ms. */
			self->errno = 0;
			setup_timer(&self->watchdog, irda_discovery_timeout,
					(unsigned long)self);
			self->watchdog.expires = jiffies + (val * HZ/1000);
			add_timer(&(self->watchdog));

			/* Wait for IR-LMP to call us back */
			__wait_event_interruptible(self->query_wait,
			      (self->cachedaddr != 0 || self->errno == -ETIME),
						   err);

			/* If watchdog is still activated, kill it! */
			if(timer_pending(&(self->watchdog)))
				del_timer(&(self->watchdog));

			IRDA_DEBUG(1, "%s(), ...waking up !\n", __func__);

			if (err != 0)
				goto out;
		}
		else
			IRDA_DEBUG(1, "%s(), found immediately !\n",
				   __func__);

		/* Tell IrLMP that we have been notified */
		irlmp_update_client(self->ckey, self->mask.word,
				    NULL, NULL, NULL);

		/* Check if the we got some results */
		if (!self->cachedaddr)
			return -EAGAIN;		/* Didn't find any devices */
		daddr = self->cachedaddr;
		/* Cleanup */
		self->cachedaddr = 0;

		/* We return the daddr of the device that trigger the
		 * wakeup. As irlmp pass us only the new devices, we
		 * are sure that it's not an old device.
		 * If the user want more details, he should query
		 * the whole discovery log and pick one device...
		 */
		if (put_user(daddr, (int __user *)optval)) {
			err = -EFAULT;
			goto out;
		}

		break;
	default:
		err = -ENOPROTOOPT;
	}

out:

	release_sock(sk);

	return err;
}

Project: linux
File: af_irda.c

static void irda_getvalue_confirm(int result, __u16 obj_id,
				  struct ias_value *value, void *priv)
{
	struct irda_sock *self;

	self = (struct irda_sock *) priv;
	if (!self) {
		IRDA_WARNING("%s: lost myself!\n", __func__);
		return;
	}

	IRDA_DEBUG(2, "%s(%p)\n", __func__, self);

	/* We probably don't need to make any more queries */
	iriap_close(self->iriap);
	self->iriap = NULL;

	/* Check if request succeeded */
	if (result != IAS_SUCCESS) {
		IRDA_DEBUG(1, "%s(), IAS query failed! (%d)\n", __func__,
			   result);

		self->errno = result;	/* We really need it later */

		/* Wake up any processes waiting for result */
		wake_up_interruptible(&self->query_wait);

		return;
	}

	/* Pass the object to the caller (so the caller must delete it) */
	self->ias_result = value;
	self->errno = 0;

	/* Wake up any processes waiting for result */
	wake_up_interruptible(&self->query_wait);
}

Project: linux
File: af_irda.c

static void irda_connect_confirm(void *instance, void *sap,
				 struct qos_info *qos,
				 __u32 max_sdu_size, __u8 max_header_size,
				 struct sk_buff *skb)
{
	struct irda_sock *self;
	struct sock *sk;

	self = instance;

	IRDA_DEBUG(2, "%s(%p)\n", __func__, self);

	sk = instance;
	if (sk == NULL) {
		dev_kfree_skb(skb);
		return;
	}

	dev_kfree_skb(skb);
	// Should be ??? skb_queue_tail(&sk->sk_receive_queue, skb);

	/* How much header space do we need to reserve */
	self->max_header_size = max_header_size;

	/* IrTTP max SDU size in transmit direction */
	self->max_sdu_size_tx = max_sdu_size;

	/* Find out what the largest chunk of data that we can transmit is */
	switch (sk->sk_type) {
	case SOCK_STREAM:
		if (max_sdu_size != 0) {
			IRDA_ERROR("%s: max_sdu_size must be 0\n",
				   __func__);
			return;
		}
		self->max_data_size = irttp_get_max_seg_size(self->tsap);
		break;
	case SOCK_SEQPACKET:
		if (max_sdu_size == 0) {
			IRDA_ERROR("%s: max_sdu_size cannot be 0\n",
				   __func__);
			return;
		}
		self->max_data_size = max_sdu_size;
		break;
	default:
		self->max_data_size = irttp_get_max_seg_size(self->tsap);
	}

	IRDA_DEBUG(2, "%s(), max_data_size=%d\n", __func__,
		   self->max_data_size);

	memcpy(&self->qos_tx, qos, sizeof(struct qos_info));

	/* We are now connected! */
	sk->sk_state = TCP_ESTABLISHED;
	sk->sk_state_change(sk);
}

Project: linux
File: af_irda.c

static void irda_disconnect_indication(void *instance, void *sap,
				       LM_REASON reason, struct sk_buff *skb)
{
	struct irda_sock *self;
	struct sock *sk;

	self = instance;

	IRDA_DEBUG(2, "%s(%p)\n", __func__, self);

	/* Don't care about it, but let's not leak it */
	if(skb)
		dev_kfree_skb(skb);

	sk = instance;
	if (sk == NULL) {
		IRDA_DEBUG(0, "%s(%p) : BUG : sk is NULL\n",
			   __func__, self);
		return;
	}

	/* Prevent race conditions with irda_release() and irda_shutdown() */
	bh_lock_sock(sk);
	if (!sock_flag(sk, SOCK_DEAD) && sk->sk_state != TCP_CLOSE) {
		sk->sk_state     = TCP_CLOSE;
		sk->sk_shutdown |= SEND_SHUTDOWN;

		sk->sk_state_change(sk);

		/* Close our TSAP.
		 * If we leave it open, IrLMP put it back into the list of
		 * unconnected LSAPs. The problem is that any incoming request
		 * can then be matched to this socket (and it will be, because
		 * it is at the head of the list). This would prevent any
		 * listening socket waiting on the same TSAP to get those
		 * requests. Some apps forget to close sockets, or hang to it
		 * a bit too long, so we may stay in this dead state long
		 * enough to be noticed...
		 * Note : all socket function do check sk->sk_state, so we are
		 * safe...
		 * Jean II
		 */
		if (self->tsap) {
			irttp_close_tsap(self->tsap);
			self->tsap = NULL;
		}
	}
	bh_unlock_sock(sk);

	/* Note : once we are there, there is not much you want to do
	 * with the socket anymore, apart from closing it.
	 * For example, bind() and connect() won't reset sk->sk_err,
	 * sk->sk_shutdown and sk->sk_flags to valid values...
	 * Jean II
	 */
}

Project: linux
File: af_irda.c

static int irda_open_tsap(struct irda_sock *self, __u8 tsap_sel, char *name)
{
	notify_t notify;

	if (self->tsap) {
		IRDA_WARNING("%s: busy!\n", __func__);
		return -EBUSY;
	}

	/* Initialize callbacks to be used by the IrDA stack */
	irda_notify_init(&notify);
	notify.connect_confirm       = irda_connect_confirm;
	notify.connect_indication    = irda_connect_indication;
	notify.disconnect_indication = irda_disconnect_indication;
	notify.data_indication       = irda_data_indication;
	notify.udata_indication	     = irda_data_indication;
	notify.flow_indication       = irda_flow_indication;
	notify.instance = self;
	strncpy(notify.name, name, NOTIFY_MAX_NAME);

	self->tsap = irttp_open_tsap(tsap_sel, DEFAULT_INITIAL_CREDIT,
				     &notify);
	if (self->tsap == NULL) {
		IRDA_DEBUG(0, "%s(), Unable to allocate TSAP!\n",
			   __func__);
		return -ENOMEM;
	}
	/* Remember which TSAP selector we actually got */
	self->stsap_sel = self->tsap->stsap_sel;

	return 0;
}